Feeding device for roasting-furnaces.



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HARRY H. STOUT, F NEW YORK, N. Y., ASSGNOR TO GENERAL CI-IElllllCAl'a4 COMPANY,

@E NEW YORK, N. Y.,

A CORPORATON OF NEW YORK.

FEEDNG DEVICE FOR ROASTING-'FURNACE incassa.

Specification of Letters Patent.

. `Application led March 7, 1913. Serial No. 752,538.

i all 'whom t may concern Be it known that I, HARRY H. Srour, acitizenof the United States and a resident of the borough of Manhattan, city, county, and State of New York, have' invented a new, useful, and lmproved Feeding Device for Roasting-Furnaces, of which the following, taken in connection with the accompanying drawings,.is a specification.

My invention .relates to roasting` furnaces, especially such `as are used for roasting pyrites or other ores, and such as are rovided with stationary hearths upon which the ore is stirred and-distributed by ra-kes or plows affixed to rotating arms, andv has for its principal object the provision of means `whereby the ore may be fed to the furnace automatically and in inl the patent' to.

regulatable quantities.

Further objects will be will otherwise appear in the following description of the embodiment of my inventionshown in the accompanying drawings,

which. illustrate my invention as applied to aroasting furnace of the well known type such as is .shown and described, for instance,

John B. Francis Herreshoif, No. 97 6,175, dated lNovember 22, 1910, andinwhich Figure 1' is a vertical section of a-portion of the furnace equipped with my improved feeding mechanism, the section passing through the secondary feeding device and Fig. 2 is a planview of a diametral portion thereof, the primary hopper being removed.

Thefurnace illustrated comprises a cylin drical. structure surrounded'by a casing 1 'and provided with a series oflsuperposed three only are shown and 1noors, of which 1 by the reference characters dicated in Fig. 2, 3 and 4the 'videdwith peripheralapertures, as 3 and central apertures, as 2 and 4. The upper Hoor. 2 constitutes a roof for the furnace and is utilized as a hearth for supporting and drying the ore before it is fed to the burning hearths formed by the floors 3 and 4 andthe other floors within the furnace.

Extending vertically through the furnace is a rotatable double walled-shaft 5 to which is affixed a plurality. of horizontally extending stirrer arms or rabble( arms 6, 'Z and 8.

The arms, 6, which are preferably'four inv number, extend over the top or roof 2 and are provided with suitablel plows or de pointed out or ioors being alternately proflecting teeth 6 which extend into the ore to agltate it and move it gradually toward the axis of the of the shafts. The ore thus impelled finally falls through the aperture 2 into the hopper of the secondary feeding device .to be hereinaftercdescribed and upon issuing from said furnace during the rotation,

Patented July '7, 1914.

device fallsupon the floor 3 upon which it is stirred and deflected toward the opening 3 by the angularly arranged teeth of they rabble arms 7 After discharging through the opening 3 upon the hearth 4, the ore is deflected in a similar manner by means of the teeth of the rabble arms 8 toward the opening 4 in said hearth. 4Thus the ore is caused yto traverse all the hearths of the furnace, its oxidation being accomplished during its passage, and is` finally discharged I fully roasted, at `the bottom of the furnace. The products of combustion pass in an opposite direction and finally issue through suitable passages at the upper portion of the furnace. A

The rabble arms are each provided with a passage-which is in communication at one end with the interior of the inner wall of the shaft 5, the other end being in commu-v nication with the annular space between the inner and outer walls of said. shaft. This annular space is in communication with the dampered" stack 9. Vith this construction it is obvious that a circulation of cooling ail' may be established for the purpose of cooling the rabble arms. The shaft 5 is journaled in suitable lower and upper bearings, the latter of which is shown and indicated by the reference number 10 land issupportedon Ibeams y11 which extend across the top of the furnace above the top 2. f

The hopper 12 of the primary feedingdevice may be of any suitable construction and is supported upon the'beams'll, near the outer edge of the furnace. The ore to be treated is fed to the hopper 12 in any well known mannerand discharges from the -orifice thereof upon the support 13 which may be a part of the bracket `4 supportingone end of the beams .11. a back which prevents the ore from d1scharging externally ofth\e casing 1, ysupport 13 is provided with an extensionfr 15 .adjustablv secured to the support by Thebolts.

Thek bracket' 14 forms and-slot connections so that it can be-fas tened in a variety of positions to exteiid'tlie' less degree toward the centerofthe furnace and thus vary the area of the support. I he position of adjustment of this edge depends in usual practice upon the talus angle, or angle of repose, of the pile of ore discharged from the hopper 12 and this, in turn, de pends upon the nature of the ore or the condition thereof, such as its dampness or the fineness of its particles. Generally it is preferable to adjust this edge so that the base of the pile of ore whatever the angle of repose may be, is .barely supported by the shelf 13 the result being that a slight disturbance of the pile will precipitate apartof the ore over the edge upon the roof 2. It will readily be seen that with such an adjust. .ent only a very small amount of power is required to remove the ore from the support. It is tobe understood however, that the edge maybe adjusted nearer to or farther from the axis of the furnace.

Rising from one or more of the rabble arms 6 and near the outer extremities thereof is a wiper support 16, the upper portion of which is provided. with an aperture angularly disposed with reference to the longitudinal axis of the arm and through this aperture extends a horizontally disposed wiper 17 which, during the rotation of the rabble arm, sweeps above the support 13. The wiper is adjustably held in position in the wiper support, in an obvious manner by a set screw 18 and, as will readily be understood, may be set to sweep over any desired area of the support 18, so as to disturb and dislodge any desired portion of the pile. of ore on said support. Owing to the angular position of the wiper, in which its outer extremitv is forward of the arm, the rotation being in the direction of the arrow on Fig. 2 of the drawings, the ore is propelled in a direction generally toward the center of the furnace andis thus caused to fall over the edge of the support 13 uponcthe; topiof the furnace therebelow. As'shown" in Fig; 2, the wiper 17 on one of the arms 6 is followed by a wiper 17 on another: arm; the two wipers may be similar or may vary as to active area or as to the degree of projection over the support 13, as'may be desired, it being understood, however, that a single wiper may be successfully used.

'The teeth 6, of the rabble arms 6 gradu ally more the ore alongthe roof 2, the ore being dried meanwhile, toward the axis of the furnace until it falls through the aper` pending annular collar secured within the aperture 2 in the roof 2, so that the ore passing through said aperture must fall into the hopper, the hopper making a scalable joint with said roof and the ore in the hcpper being the medium for sealing said oint. The bottom of the hopper is provided with a depending spout Q0, through the orifice of which the ore is fed from the hopper upon the support or hearth 3. The spout 20 provided with a` telescopic extension 91 which is vertically slidable with reference to the fixed portion of the spout so that the. distance between the hearth 3 andl the discharge orifice of the hopper may he varied. In order to insure a ready and accessible adjustability of the extension Q1, I have provided a member 2Q secured at its lower end to said extension and screw threaded its upper end, the screw threaded portion extending through a bracket Q3 suitably supS ported in one of the arms 6 and being engaged thereabove by a handle-nut 24. It will be readily understood that manipulation of the nut will result in the-raisin@ or lowering of the extension 21. The ex ai sion extends betweenadjacent rabble arms 7 but is not interferedwith by them because the feeding device rotates at the same speed as the rabble arms.

If there were no movement of thevparts the ore discharged, by vthe secondary feeding device would form a conical pile upon the support or hearth 3, which would increase 1n size until it closed the orice of the device. In the operation of the furnace, however, the feeding device moves in a circular path, the hearth 3 being, of course, stationary, with the result that the ore is distributed upon the hearth. This ore is continually being moved toward the aperture 3 by the teeth of the rabble arms 7, lso that when properly operated there is a continuous discharge from the orifice, while at the same time the hopper spout is atv all times filled with ore and gaseous products are prevented from escaping therethrough.

The employment of primary and secondary feeds of thev kind described insures a proper and controllable introduction of ore to the furnace. The primary feed is adjustable so that `it can be accommodated to'ores of .varying characteristics and, Whatever the ore, any given quantity, within limits, of course, can be fed. The' feeding is in this case intermittent while in the case of the secondary feeding device, it is continuous. In both cases, however, the feeding is controllable and regulatable; by cooperation of the two adjusted devices a proper and delicately variable amount of ore is capable of being introduced into the furnace I claim:

1. A feeding device comprising a hopper provided with a discharge orifice, a support below said hopper and spaced from said orifice,` said support being variable in area and adapted to receive and support the ma, terial discharged from said hopper, and

means for removing a portion of said naa-v terial from the support.

2. A feeding device comprising a support, a-hopper provided with a discharge orifice spaced above said support whereby material may be discharged from said orifice to forln a pile upon said support until the pile thus formed closes said orifice, said support being adjustable in area to accommodate materials of varying angles` of repose, and means for removing a portioni of the material from said pile.

l roasting furnace, the combination vofa pluralityof stationary floors, a rotatable shaft extending through said floors, an annular hopper secured to and surrounding said shaft and making a scalable joint with one of said floors, said hopper having a discharge orifice spaced above the other of said floors, and means said hopper. l

4. In a roasting furnace a stationary top and a stationary hearth therebelow, the combination of an adjust-able primary feeding device for feeding ore to the top, an adjustable secondary feeding device secured to a movable part of the furnace and provided with an orifice spaced above and adapted for feeding material into to move over said hearth for feeding ore to and distributing it upon said hearth, andk means for feeding to the secondary device the ore discharged from the primary device.

5. In a roasting furnace having a stationary top and a stationaryl hearth therebelow, the combination of an adjustable primary feeding device for feedingv ore tothe top, an adjustableI secondary feedingl device for feeding ore to the hearth, said'secondary device being provided with, a discharge orifice spaced above said hearth, means for supporting said secondary device and mov; ing it in a direction ysuch that the distance between said orifice and said hearth is maintained substantially constant, whereby the ore' discharged by'said secondary device is distributed upon said hearth, and means for feeding to the secondary device the ore discharged from the primar device.

In testimony whereof, have hereunto set my hand in the presence of two subscribing witnesses.

i r HARRY ii. sToUT.

Witnesses: p

THEODORE N.I POWELL, JOHN A. FERGUsoN. 

